Doublet Suppression in the Principal Series of Cesium

The suppression of the doublet structure in mixtures of cesium and foreign gases with increasing foreign gas concentration is investigated. The observations are made in absorption with the foreign gases helium, neon, argon, xenon, and neopentane. The foreign gases investigated which demonstrate complete suppression, xenon and neopentane, also produce satellites on both doublet components. The growth of the satellites with increasing foreign gas concentration is shown to produce anomalously broadened lines, considering that the satellite and its parent line together constitute the same transition. The anomalous broadening of the components results in excessive loss of measured absorption as the center of the lines is depressed and the absorption in the wings predominates. Assuming a minimum detectable absorptivity of 0.03, the absorption of the weaker components (${}_{}{}^2{}_{}{}^{}P_{\frac{1}{2}}^{}{}_{}{}^{}$) is seen to be undetectable for many of the higher doublets, while the strong components (${}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$) remain detectable, although considerably broadened.